Drywall/sheathing cutting tool and method

ABSTRACT

A rotary cutting tool is provided for cutting an opening in a sheet of material (e.g., drywall) around a pre-installed item (e.g., an electrical box). The cutting tool may include a shaft, at least one cutter, a guide tip and a shoulder formed by a lower edge of the cutter adjacent the guide tip. The shoulder may have a width that corresponds to the width of a wall of the pre-installed item. The width of the shoulder may be equal to the width of the wall, or it may be slightly greater than the width of the wall. The guide tip may include a bearing to prevent marring of the wall of the item when the guide tip is rotating and in contact with the wall. An adjustable collar and corresponding bearing may also be disposed around the shaft for controlling a preferred cutting depth of the cutter. The cutting tool may be engaged with any suitable rotary tool, including one having an adjustable table for controlling a preferred cutting depth of the cutter. Related methods of using a cutting tool to cut an opening for receiving the item or box are also provided. The rotating guide tip may be moved into contact with the wall and the shoulder may be positioned above and/or in contact with an upper edge of the wall. The cutting tool is then moved around the wall while rotating to cut an opening in the material through which the item or box may be positioned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention generally pertains to hand tools, and moreparticularly to a rotary cutting tool or bit for use with a power routeror other rotary tool during the installation of drywall or sheathing.

2. Description of the Related Art

It is well known in the construction industry that the interior walls ofmost homes and many commercial buildings in the United States areconstructed using drywall. It is also well known that a variety of stepsin the building process are taken before the drywall is installed, or“hung” (e.g., electrical wiring and electrical outlet boxes, switchboxes, vent fans, and certain canister and other lights and devices areinstalled; telephone wire and telephone boxes are installed; cable wireand cable boxes are installed; speaker wire and recessed speaker boxes;vents; returns; plumbing pipes such as a drain; etc.). It is furtherknown that these electrical, telephone, cable, etc. boxes and otherdevices extend past the “studs” (typically wood boards) to which theyare attached by a distance generally equal to the thickness of thedrywall that is to be attached to the studs. As such, when the drywallis installed, it is necessary to cut a hole or opening, generallyrectangular or circular in shape, through which the outlet/switch boxesetc. extend, such that the outer edges of the boxes or devices aregenerally flush with the exterior surface of the drywall once thedrywall is secured to the studs. The present invention relates to theprocess of cutting the openings or holes for the boxes or other devices.

Heretofore, these openings have been cut out or created in a variety ofways. One way to cut them out is “by hand” using a drywall knife or saw.Another way to cut them out is by using a power rotary tool such as arouter and router bit. Examples of ways in which openings have been cutout are disclosed in various patents, such as, U.S. Pat. Nos. 4,359,302(Payne), 4,384,396 (Smolik), 5,143,490 (Kopras), 6,452,097 (DeWall),6,758.639 (Risen, Jr.) and 6,867.369 (Wiggens), for example. As willbecome apparent from the following description and discussion, thepresent invention is directed to an improved rotary tool and relatedmethod of cutting out these openings that overcomes the deficiencies inthe previous methods and tools. More specifically, the present inventiondoes a much better job of eliminating inaccuracies in precutting theseopenings before and during the installation of the drywall, such as theexcessively oversized cutout openings that are created using currentlyavailable rotary bits. The present invention also reduces installationtime.

SUMMARY OF THE INVENTION

In a broad aspect, the present invention is directed to a rotary cuttingtool comprising: a shaft, at least one cutter, a guide tip, and ashoulder formed by a lower edge of the cutter adjacent the guide tip.Another feature of this aspect of the present invention is that theshoulder may have a predetermined width substantially corresponding tothe width of a wall of an item installing during construction of astructure. Another feature of this aspect of the present invention isthat the item may be one of an electrical box, a telephone box, a cablebox, a vent fan, a canister light, and a recessed speaker box. Anotherfeature of this aspect of the present invention is the shoulder may havea predetermined width slightly greater than the width of a wall of anitem installing during construction of a structure. Another feature ofthis aspect of the present invention is that the width of the shouldermay be approximately 1/16 of an inch greater than the width of the wallof the item. Another feature of this aspect of the present invention isthat the tool may further include a bearing disposed around the guidetip. Another feature of this aspect of the present invention is that thetool may further include an adjustable collar disposed around the shaftfor controlling a preferred cutting depth of the cutter. Another featureof this aspect of the present invention is that the tool may furtherinclude a bearing disposed around the shaft adjacent the collar. Anotherfeature of this aspect of the present invention is that the tool mayfurther include a rotary tool engaged with the shaft and having anadjustable table for controlling a preferred cutting depth of thecutter.

In another aspect, the present invention may comprise a rotary cuttingtool comprising: a shaft, at least one cutter, a guide tip, and ashoulder formed by a lower edge of the cutter adjacent the guide tip,the shoulder having a predetermined width corresponding to the width ofa wall of an item installing during construction of a structure. Anotherfeature of this aspect of the present invention may be that the item maybe one of an electrical box, a telephone box, a cable box, a vent fan, acanister light, and a recessed speaker box. Another feature of thisaspect of the present invention may be that the item may be that thewidth of the shoulder is slightly greater than the width of the wall ofthe item. Another feature of this aspect of the present invention may bethat the item may be that the width of the shoulder is approximately1/16 of an inch greater than the width of the wall of the item. Anotherfeature of this aspect of the present invention may be that the item maybe that the tool may further include a bearing disposed around the guidetip. Another feature of this aspect of the present invention may be thatthe tool may further include an adjustable collar disposed around theshaft for controlling a preferred cutting depth of the cutter, and abearing disposed around the shaft adjacent the collar. Another featureof this aspect of the present invention may be that the tool may furtherinclude a rotary tool engaged with the shaft and having an adjustabletable for controlling a preferred cutting depth of the cutter.

In still another aspect, the present invention may be a method ofcutting an opening in a sheet of material to receive a pre-installeditem having a wall forming a periphery, comprising: inserting a rotatingcutting tool through the material at a position within the wallperiphery; moving the rotating cutting tool towards the wall until aguide tip of the cutting tool contacts the wall and a shoulder on thecutting tool is positioned above an upper edge of the wall; and movingthe rotating cutting tool around wall periphery while maintaining theguide tip in contact with the wall and maintaining the position of theshoulder above the upper edge of the wall. Another feature of thisaspect of the present invention may be that the shoulder of the cuttingtool is positioned above the upper edge of the wall and in contact withthe upper edge of the wall, and maintained in that position as therotating cutting tool is moved around the wall periphery. Anotherfeature of this aspect of the present invention may be that the shoulderon the cutting tool has a width substantially corresponding to a widthof the wall. Another feature of this aspect of the present invention maybe that the shoulder on the cutting tool has a width that is slightlygreater than a width of the wall.

Other features, aspects and advantages of the present invention willbecome apparent from the following discussion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side view of a specific embodiment of a cutting tool of thepresent invention.

FIG. 2 is a front view showing an interior wall with some drywallattached thereto and the studs to which the drywall is attached shown bydashed lines, and also showing a sheet of drywall that has not yet beenfully attached to the studs, as indicated by an electrical box shown indashed lines.

FIG. 3 is a cross-sectional view taken along line 3-3 of FIG. 2.

FIG. 4 is a side view in partial cross section showing the toolillustrated in FIG. 1 being used to cut an electrical box opening indrywall.

FIG. 5 is a side view in partial cross section showing a depthcontroller attached around the cutting tool illustrated in FIG. 1.

FIG. 6 is a side view showing the cutting tool illustrated in FIG. 1attached to the chuck of a high speed rotary tool having an adjustabletable being used to control how far the cutting tool extends through thedrywall.

FIG. 7 is a side view of another specific embodiment of a cutting toolof the present invention, this one having a rotatable bushing or bearingattached to the tip of the tool.

While the invention will be described in connection with the preferredembodiments, it will be understood that it is not intended to limit theinvention to those embodiments. On the contrary, it is intended to coverall alternatives, modifications, and equivalents as may be includedwithin the spirit and scope of the invention as defined by the appendedclaims.

DETAILED DESCRIPTION OF THE INVENTION

Referring to the drawings in detail, wherein like numerals denoteidentical elements throughout the several views, there is shown in FIG.1 a specific embodiment of a cutting tool 10 of the present inventionhaving a shaft 12, a plurality of helical cutters 14, 16, and 18, and aguide tip 20. The transition from the last or bottom cutter 18 and theguide tip 20 defines a shoulder 22.

Referring now to FIG. 2, a portion of an interior wall 24 is shown whichis made using a number of vertical studs 26 shown as dashed lines. Asheet of drywall 28 is shown secured to the studs 26 and includes anelectrical box opening 30 which is snugly fit around an electrical box32. An electrical box 32 is being used here and in the Figures forillustration purposes only, and should not be taken as a limitation. Thepresent invention can by used for cutting openings for any type of box,fixture or other device. Another sheet of drywall 34 is shown in theprocess of being secured to the studs 26, but before an opening has beencut for the electrical box 36, which is illustrated by dashed lines.This is better shown in FIG. 3, which is a cross-sectional view takenalong line 3-3 of FIG. 2. Looking at FIG. 3, it can be seen that theupper edge of the sheet of drywall 34 has been secured to a top plate 38that forms part of the wall frame along with studs 26. It can further beseen that the sheet of drywall 34 is being held out away from the studs26 by the electrical box 36. In other words, the sheet of drywall 34 isresting against the electrical box 36. It is at this point that anopening is ready to be cut in the sheet of drywall 34 so that thedrywall 34 will fit over and around the electrical box 36.

Referring now to FIG. 4, the cutting tool 10, which is attached to arotary tool such as a high speed router (not shown), is pushed throughthe drywall 34 while spinning at a location somewhere inside the sidewalls 37 of the electrical box 36. With the shoulder 22 of the cuttingtool 10 preferably positioned approximately flush with an inside surface35 of the sheet 34, the rotating cutting tool 10 is then moved towardsone of the side walls 37 until the guide tip 20 comes into contact withthe side wall 37 and the shoulder 22 is resting on an outer edge 40 ofthe electrical box 36. At this point, with reference to FIG. 1, it canbe seen that the width “W” of the shoulder 22 is preferably about equalto the width of the side walls 37. In a specific embodiment, the width“W” of the shoulder 22 may be slightly greater than the width of theside walls 37 (e.g., by 1/16 of an inch) so as to provide a bit ofclearance for the electrical box 36 to fit through the opening being cutout with the cutting tool 10. Once the shoulder 22 is resting on theedge 40 and the guide tip 20 is touching the side wall 37, the cuttingtool 10—while rotating—is moved completely around the inside of theelectrical box 36, keeping the shoulder 22 in contact with the edge 40and the guide tip 20 in contact with the side walls 37 at all times.Once the complete periphery of the inside of the electrical box 36 hasbeen traversed by the cutting tool 10, then an electrical box openingsuch as opening 30 will have been created or cut out, at which point thedrywall 34 may be pushed in around the electrical box 36 and secured tothe studs 26.

Referring now to FIG. 5, an adjustable collar 42 may be provided tocontrol the depth that the cutting tool 10 extends into the drywall 34.The collar 42 may be a tubular member disposed around the shaft 12 andhaving a threaded bore 44 adapted to threadably engage a hex head screw46. The screw 46 functions to secure the collar 42 to the shaft 12 ofthe cutting tool 10 at the desired depth setting. A bearing 47 isdisposed between the collar 42 and the drywall 34 so as to prevent therotating collar 42 from burning, shredding or otherwise damaging thedrywall 34. As discussed above, the preferred depth setting is set suchthat the shoulder 22 is substantially flush with the inside surface 35of the drywall 34 while at the same time resting against the edge 40 ofthe side walls 37 of the electrical box 36.

FIG. 6 illustrates another approach to controlling the depth that thecutting tool 10 extends into the drywall 34. In this embodiment, thecutting tool 10 is shown with its shaft 12 tightened in a chuck 48 of ahigh speed rotary tool 50, such as a Dremel® rotary tool, which isprovided with an adjustable table 52. The table 52 is preferablyadjusted such that the shoulder 22 on the cutting tool 10 issubstantially flush with the inside surface 35 of the drywall 34 whileat the same time resting against the edge 40 of the side walls 37 of theelectrical box 36.

With reference to FIG. 7, in another specific embodiment, the cuttingtool 10 may be provided with a rotatable bearing or bushing 54 disposedaround the guide tip 20. In this manner, the rotating guide tip 20 doesnot come into direct contact with the side walls 37 of the electricalbox 36, thereby avoiding the potential for the guide tip 20 to burn theside walls 37 when rotating at a high speed.

It should now be readily apparent that the cutting tool and method ofthe present invention has a number of benefits and advantages over theprior tools and methods of cutting openings in drywall. For example,with the present invention, overcutting or creating excessivelyoversized openings that require repair or replacement is avoided. Theaspect of the present invention directed to limiting the depth ofpenetration into the boxes and other devices minimizes the risk ofdamage to wires and parts inside the box or device. Another advantage ofthe present invention is its increased efficiency of drywallinstallation and reducing required accuracy of measurements.

It is to be understood that the invention is not limited to the exactdetails of construction, operation, exact materials or embodiments shownand described, as obvious modifications and equivalents will be apparentto one skilled in the art. For example, as mentioned previously, theFigures and above description have used an electrical box as the itemfor which an opening is needed. But that that should not be taken as alimitation, as the present invention may be employed for creatingopenings for any type of box, device, fixture, etc., including but notlimited to electrical outlet boxes, electrical switch boxes, vent fans,canister lights, telephone boxes, cable boxes, recessed speaker boxes,vents, returns, plumbing pipes, plumbing drains, brackets, receivingpieces, template devices, doors and windows. Also, while the presentinvention has been described and illustrated in connection with a sheetof drywall, the present invention may be employed when cutting anopening in any type of material, whether it be drywall, sheathing,gypsum board, plywood, peg board, pressed board, siding, etc.Accordingly, the invention is therefore to be limited only by the scopeof the appended claims.

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 18. A method of cutting an opening in asheet of material to receive a pre-installed item having a wall forminga periphery, comprising: inserting a rotating cutting tool through thematerial at a position within the wall periphery; moving the rotatingcutting tool towards the wall until a guide tip of the cutting toolcontacts the wall and a shoulder on the cutting tool is positioned abovean upper edge of the wall; and moving the rotating cutting tool aroundthe wall periphery while maintaining the guide tip in contact with thewall and maintaining the position of the shoulder above the upper edgeof the wall.
 19. The method of claim 18, wherein the shoulder of thecutting tool is positioned above the upper edge of the wall and incontact with the upper edge of the wall, and maintained in that positionas the rotating cutting tool is moved around the wall periphery.
 20. Themethod of claim 18, wherein the shoulder on the cutting tool has a widthsubstantially corresponding to a width of the wall.
 21. The method ofclaim 18, wherein the shoulder on the cutting tool has a width that isslightly greater than a width of the wall.
 22. The method of claim 21,wherein the width of the shoulder is approximately 1/16 of an inchgreater than the width of the wall.
 23. The method of claim 21, whereinthe pre-installed item is an electrical box.
 24. The method of claim 21,wherein the sheet of material is drywall.
 25. A method of cutting anopening in a sheet of material to receive a pre-installed item having awall forming a periphery, comprising: positioning the sheet of materialadjacent the pre-installed item; inserting a rotary cutting tool throughthe sheet of material at a position within the wall periphery; movingthe rotary cutting tool towards the wall until a guide tip of the rotarycutting tool contacts the wall; moving a shoulder on the rotary cuttingtool into contact with an upper edge of the wall; and moving the rotarycutting tool around the wall periphery while maintaining the guide tipin contact with the wall and maintaining the shoulder in contact withthe upper edge of the wall.
 26. The method of claim 25, wherein theshoulder on the cutting tool has a width substantially corresponding toa width of the wall.
 27. The method of claim 25, wherein the shoulder onthe cutting tool has a width that is slightly greater than a width ofthe wall.
 28. The method of claim 25, wherein the width of the shoulderis approximately 1/16 of an inch greater than the width of the wall. 29.The method of claim 25, wherein the pre-installed item is an electricalbox.
 30. The method of claim 25, wherein the sheet of material isdrywall.
 31. A method of installing a sheet of drywall around anelectrical box mounted to a stud that forms part of a structure,comprising: attaching an upper portion of the sheet of drywall to aportion of the structure at a location above the electrical box suchthat the sheet of drywall is resting against the electrical box; pushinga rotary cutting tool through the sheet of drywall while spinning at alocation within a wall that forms a periphery of the electrical box;moving the spinning rotary cutting tool towards the wall until a guidetip of the rotary cutting tool contacts the wall; moving a shoulder onthe spinning rotary cutting tool into contact with an upper edge of thewall; and moving the spinning rotary cutting tool around the wallperiphery while maintaining the guide tip in contact with the wall andmaintaining the shoulder in contact with the upper edge of the wall. 32.The method of claim 31, wherein the shoulder on the rotary cutting toolhas a width substantially corresponding to a width of the wall.
 33. Themethod of claim 31, wherein the shoulder on the rotary cutting tool hasa width that is slightly greater than a width of the wall.
 34. Themethod of claim 31, wherein the width of the shoulder is approximately1/16 of an inch greater than the width of the wall.